Boy am I glad I learned math in the 1960/70's not 2020's!

I was asked by my Grade 6 daughter today (2023.10.19) how to do the following assignment.

Can someone tell me in what branch of Math this makes sense? Tell me the point? Tell me maybe even the value? Point me at a URL that explains how this math concept works?

I have looked at this set of problems. To be fair, the header on the previous page is "Division by 10, 100, 1000"

I’m sure some BRILLIANT person came up with this trick.

I can see that the empty circles never add up to more than 9, so it his something to do with division by 10 (full disclosure: The previous page says it is for division by 10’s 100’s etc..,)

But why 9/3 and 6/3 for 15/3? No idea at all – it is just some random trick Mena question “find the hidden pattern – it doesn’t have to make sense.”

I’ve scanned back through the rest of the book and I don’t see anything that matches the same pattern.

I can come up with a pattern (answers) that perfectly fits with the sample of 4. I would count the rows to select the divisor. (so /3 in the sample) I would multiple the rows by columns to get the dividend – but then what is the point – given you START with the dividend and divide by the divisor! I would then, starting from the right, count until I have 9 empty circles, then, if there are more circles in that column, I would fill in the circles in THAT column and all the columns to the left. (and if THEY added up to 99, I would start putting in an X instead of filling in to indicate more than 100.) Then I would count the empty circles, filled in circles and X circles and write them in reverse order. Tada! I have solved the Mensa test having learned and understood absolutely nothing about division. But getting lots of practice carefully filling in circles.

I can see there is a pretty good CHANCE, given I am smart enough, that that PATTERN will give me the correct answer – without ANY knowledge of division.

WHY it is the correct answer? – no clue. What concept it is trying to teach? – equally, I have NO clue.

Worthy of putting on one of my web sites as an example of stupidity of modern math teaching? Probably. But to be FAIR – I’m assuming that BEFORE she was given this assignment, she was given a better explanation, so my web site post, while fun, won’t be entirely fair. I’ll probably do it, and then put the ‘real’ pattern/reason in later.

Where we are currently at on this: Waiting for results. 1. Is there a text book that gives an explanation for this trick? 2. Can the teacher tell you the POINT of this trick?

I have confirmed that there is no other text book, so nothing written to explain anything about it.

From a teacher who is, in Alberta, qualified to teach it and got over 95% in University Elementary School teaching classes:

So I was right! It is a Mensa level question, designed to be a magnitude order more difficult!

But if anyone can tell me how it makes sense - I would still like to know.

One of our readers, who also homeschools his boys, replied this way:

Ignore my answer; it doesn't fully match the pattern

I retract my retraction, my pattern does work in all the listed cases.

Got a response back from her teacher: Just skip those exercises, they just confuse the kids, it is OK to use traditional math instead.